Method of producing paper bags



1953 w. s. BLIZARD 2,645,166

METHOD OF PRODUCING PAPER BAGS 2 Sheets-Sheet 1 Filed Aug. 5; 1950 Y z il 1 I L 9\ E a 2 I l I 4 l I l I t i 1 (d r 'J K 20 44 -L- w FIG. 2.

FIG.

I INVENTOR.

WALTER 3, BL IZARD ATTORNEYS.

July 14, 1953 Filed Aug. 5, 1950 w. s. BLIZARD I METHOD-OF PRODUCINGPAPER BAGS 2' Sheets-Shee t 2 WALTER s. BL 2400 BY MW ATTORNE 5.

. INVENTOR.

Patented July 14, 1953 STATE j 2,645,166 s PATENT OFFICE METHOD orPRODUCING PAPER BAGs 'Walter s. Blizard, Philadelphia, Pa., assignor toWolf Brothers, Inc., Philadelphia, Pa., a cor- 1 poration ofPennsylvania Application August 5, 1950, Serial No. 177,875

2 Claims. 1 f This invention relates to paper bags and more particularlyto the formation of a blank used in themanufacture of a paper bag orenvelope. iIt 'hasbeen the practice of manufacturers of hosiery when.pa'ckingthe hosiery, for example, whenpacking a dozen pairs ofstockings in a box; toiwrap each of the stockings around a piece ofpaper or cardboard with rounded corners to holdthem in flat'form as theyare placed in a box and to facilitate their removal from the box singlyby the retailer. I

More recentlythe practice has been to wrap the stockings around a paperbag, thus providing a bag into whichflthe stocking may be placed bytheretailer after being shown to the customer and providing a convenientcarrying bag for the customer. The trade has encountered diiliculties inthis practice in that the sharp outside corners of the conventionallyformed paper bag would frequently catch or snag the threads in finehosiery. It has become necessary, therefore, for manufacturers of thepaper bags to run the bag through an additionalioperation after the bagis completely formed wherein the pointed corners of the bag are sheared01f to produce corners of rounded form to eliminate the sharp pointswhich frequently caused damage to the stockings as the stockings wereremoved from around the bag.

It is an object of the present invention to provide a paper bag which asformed from the blank will have rounded corners.

I It is a further object of the present invention to providesuccessively, from a strip or web of paper, bag blanks which when formedinto bags will produce bags which have rounded corners.

These and other objects of the invention will become apparent from thefollowing description when read in conjunction withthe accompanyingdrawing in which? I Figure 1 is a plan viewof a bag blank formed inaccordance with the present invention; v

Figure '2 is a back-viewof a bag formed from a blank such as is shown inFigure 1; t

Figure 3 is a schematic showing of a portion of a bag forming machine;

Figures 4 and 5 are showings of a portion of the machine shown in Figure3 in successive operating positions;

I Figure 6 is a front view of a chip cutting roller; I

Figure 7 is a side view of the left side of the chip cutting roller asviewed in Figure 6; and

Figure 8 is a side view of the rightside of the cutting roller as viewedin Figure 6.

Referring to the figures there is shown a bag having a rear panel 2, afront panel 4, a closing flap '6 and side flaps or side seams 8. Theboundary between the frontand rear panels is defined by the constructionline ii which represents the bend line framing the bottom 'of the bagwhen the bag is formed with the front andrear panel substantially in theadjacent portion and with the side flaps 8 folded over on the bendequally well be constructed of fabric or plastic well selected to bebelow the construction line l9.

material, or of materials such as cellophane and the like. t

The upper portion of the front panel 4, has

outer corners formed 'by the curved portions III which merge into thecurved portions H which are of a form coincident with portions of thecircumferences of the small circles I5 shown in construction lines. Theconstruction line I3 is a line extending transversely of the bag joiningthe centers of radius of each of the two'construction lined circles [5.The construction line l4 represents the score line on which the closingflap is folded to close the bag opening of the finished bag as shown inFigure 2." It will be noted that' this score line crosses the edges ofthe-bag in reons of the curvatures H.

lel to each other and are of concaved form with respect to the edges ofthe bag blank. The curved portions 10 of the bag blank provide therounded upper corners of the finished bag as shown generally at [2 inFigure 2 when the bag closing flap has been folded down.- It will alsobe noted that the intersection of the bag flap bend line with the edgesof the bag in the vicinity of the concaved or curved side portions Hprovidesthe completely rounded corners i2 which extend to the edge ofthe flap 4 and avoid the existence of an edge at the bend line of theflap which could possibly snag the threads of even the finest hosiery.The spacing between the line [3' and the line I 4 will be preferablyapproximately onesixteenth of an inch and the radius of the curvature llmust be such that the line M will cross the edge of the blank in theregion of this curvature.

The edges of the blank from which the bag is formed have in the vicinityof the bend line 3 the notches or indentations shown generally at Itwill be noted that these indentations are formed with the arcuate baseportions I6 which are portions of the edges of the bag blank lyingcoincident with the circumference of the small circles ll shown inconstruction lines and having their centers joined by the transverseconstruction line 19. Adjacent to the curved portions l6 are the curvedportions 20 and'Zl.

shown in Figure l as being above the line I9, it should benoted as willbe hereinafter described morefully'that this displacement could beequally Thus the bend line crosses the edge of thebag blank in a region'where the edges of the bag blank are not paral-- The bend line 3 isdisplaced from the construction circle center line l9 by approximatelyone-sixteenth of an inch. While this displacement is The essentialconsiderations are that the displacement of the bend line 3 isapproximately onesixteenth of an inch from the bend line [9 and thedisplacement of the bend line I3 is also approximately one-sixteenth ofan inch from the bend line 14 and that the arcuately'concaved edges Hand are of a sufiicient extent that displacement of the bendlineslwithin'bne-Sixteenth of an inch in either direction will not carrythe bend lines more than a limited extent beyond the regions of thecurved edges H and I6.

As will become clear from the discussion contained hereinafter, thedimension between the bend line [3 and the bend line 3 is a fixeddimension and for most bags the one-sixteenth of an inch dimensionaffords ample space for nor-' mal manufacturing tolerances which mayresult in displacement of thesebend lines without carrying either of thebend lines too far beyond their associated construction line. Thiformation of the edges of the bag blank in the'region of the bend line 3results in a bag having the rounded lower corner H! as shown in Figure 2and the arcuately 'concaved portions l6 of the edges of the bag affectthe complete avoidance of any 1 The formation of thepresent bagis accomaplished by use of a conventional bag forming machine of a typewell'known to the art, the essential portions of whichare showndiagrammatically in Figure 3. In such a machine, the

strip or web of paper 22 is fed from a supply roll 4 not shown andpasses over a roller 24 which mounts a pair of side chip cutting discs,one of which is shown in Figures 6 7 and 8. The other disc of the pairwould obviously be of the opposite hand inasmuch as each disc cuts oneof the sides of the paper strip to form the side contours of the bagblank. Working against the knife edges of the cutting discs are theanvil rollers 26 and 28.

Heretofore, the chip cutters have been formed from a roller havingbolted-to one front face thereof a sheet of steel of slightly greaterdiameter than the roller extending for a sufficient portion of thecircumference of the roller and having its end portions bent outwardlyfrom the face of the roller in order to leave uncut the portion of thepaper strip which is to become the side seams of the bag. While thisconstruction was entirely satisfactory for forming the bends cut at 46and 44 in the bag blank, this type of cutting blade cannot be formed soas to make cuts of the radius shown at H and [6 of the bag blank inFigure 1.

'Referring to Figures 6, 7 and 8, there is shown a disc 30 which hasformed on its surface a hardened knife edge 32 which extends around thedisc 30 for a portion of its circumference. As the paper strip is passedthrough the machine, it is cut so as to form successively the back panel2 of the bag front panel 4 and the closing panel 6 of the bag.

The cutting disc shown in the figures is the disc used to cut the righthand side of the bag blank shown in Figure 1. The disc is rotatedcounterclockwise as shown by thev arrow 35 in Figure 6.

The portion of the cutting edge extending from the location indicated bythe numeral 34 and extending upwardly and around the roller toapproximately the location indicated by the numeral 36 is used to cutthe chip from the bag back panel within the portion of the blank boundedby the numerals 34 and 36 in Figure l. The

portion of the cutting edge in the vicinity of the numeral 38 will cutthe curved portion 2| of the bag blank, the portion 40 of the cuttingedge will cut the radius portion l6 of the bag blank, the portion 42 ofthe cutting edge will cut the curved portion 20 of the bag blank, andthe portion of the cutting edge 44 will cut the bevelled end 44 of theside flap 9 of the front of the bag front panel. The width of the stripof paper fed into the machine is selected to be equal to the width ofthe bag front panel 4 and its associated side fiaps 8, thus the cuttingedge of the chip cutter passes oil the paper somewhere beyond thelocation on the cutter indicated by the numeral 44 and returns on thepaper in the region of the numeral 46 which serves to cut the bevelledend 46' of the front of the upper portion of the side flap 8. Theportion 48 of the cutting edge serves to cut the curved portion IU ofthe bag blank, the portion 50 of the cutting edge serves to cut thearcuate edge portion H of the bag blank, the portion of the cuttingwheel 52 cuts the straight edge of the flap 52', and thereafter thecutting edge at location 34 again begins to cut the edge of the backpanel of the next successive bag at a position indicated at 34" ofFigure 1.

Thus it will be apparent that with a chip cutting roller such as shownin Figures 6, '7 and 8 mounted on the end of the roller 24 in Figure 3toward the viewer and with a chip cutting roller of reverse formationmounted on the end of the roller 24 away from the viewer the paper strip22' leaving the roller 24 will have the side formation of the bag blankshown in Figure l. The continuation of the strip is indicated by theconstruction lines 34" and 52" in Figure 1. The edge 56 of the flap andthe edge 58 of the ba back are cut out at a later operation which willbe hereinafter described, thus the strip 22' is still a continuous striphaving a side formation resultin from the removal of the side chips fromthe-edges of the paper strip by the two chip cutting rollers.

There is shown generally at B6 in Figure} a conventional mechanism forfolding the side flaps or side seams 8 inwardly on the bend lines 9.This apparatus includes a pair of guide rollers 68 and curved metalguide members 10 as are well known in the art and results in forming theside seams 8 which are outstanding in the portion of the strip indicatedas 22' causing them to be folded over on the strip in the portion of thestrip indicated at 22".

The paper strip 22" is fed over the roller 60 whereupon the extendedportions of the roller 62 serve to spread a suitable adhesive on the--folded side seams 8. The extended portions of the roller 62 with eachrotation thereof are moistened with a suitable adhesive by aconventional adhesive dispenser as indicated at 64. It should be notedthat subsequently when the bag is formed the side seams 8 will adhere tothe inside of the back panel 2 of the bag as shown in Figure2.

The strip 22" is then fed through the bag forming rollers 12 and 14. Theroller 12 in.-

eludes the two extending blade portions 16 and 18 and the roller- 14includes the slotted portions 11 and 19 which are adapted to receive theextended blade portions 76 and 18 respectively of roller 72. The slot 11contains a spring loaded clamp bar 80. The roller 14 also includes thecutting member 82 which, as hereinafter described, serves to sever thesuccessive bag blanks from the strip formin the edge 56 of the backclosing flap and the edge 58'of the bag back panel.

The paper strip 22" is fed between the rotating rollers 72 and M and asthe rollers rotate the extending blade 76 presses a portion of the paperstrip into the slot 11 wherein it is clamped by the spring loaded bar 80and as the roller 1Q rotates carries with it the double folded strip asindicated generally at 84 in Figure 4. The bend in the bag blank formedin the slot TI is the bottom fold or bend line 3 of the :bag as shown inFigure 1.

The tray 86 is provided as a support for the extended end of the strip22" in Figure 1 and provides an edge about which the strip is drawn asthe strip is folded as shown in Figure 4. A pair of rollers 88 areadapted to bear against the edges of the strip as the bag is beingformed against the roller 74 in order to press the side portions of thebag back panel 2 against the adhesive coated folded in side seamportions 8. As the rollers 12 and 14 continue to rotate the extendedblade portion 18 of roller 12 engages the slot 79 of roller 14 andpresses the strip into the slot providing the score line I 4 across thebag blank thus locating the bend line H! of the bag closing flap. a

As the roller 14 continues to rotate the cutting blade 82 comes incontact with an anvil portion of the roller 12 and cuts the edge 56 ofthe bag closing flap thus severing the formed bag from the strip 22" andat the same time cuttin the edge 58 of the bag back of the nextsucceeding bag blank. By means of a cam release mechanism not shown, thespring bar 80 is moved to release the lower end of the bag, as showngenerally at 90- in Figure 5, and the finished bag drops to a conveyermechanism not shown whereby it is carried from the machine and therollers 12 and 14' continue their rotation immediately commencing theformation of the next succeeding bag.

It will be appreciated that the bag forming apparatus described hereinis a conventional type of bag forming machine well-known to the artwhich has been modified by means of the chip cutting wheel described inconnection with Figures 6, 7 and 8 in order to'produce a bag blank suchas shown in Figure 1. It will also be appreciated that the arrangementof the sequence of operations, namely the chip cutting, the side seamforming, the application of adhesive, the formation of the bag, and thesevering of the bag from the strip may be modified without departingfrom the invention as set forth herein relating to a method of cutting aba blank to provide a finished bag which will not have the pointedcorners hereinbefore described.

Referring to the roller 12,- it will be observed that the extended bladeportions 16 and 18 establish a fixed and constant dimension between thebend lines 3 and I4 01 the bag and while these two bend lines may varyslightly in position with respect to the lines 19 and I3, it will beapparent that variation with respect to each of those lines will be thesame. The one-sixteenth of an inch dimension provided by the blank shownherein as being the limit of the displacement of the line l4 upwardly orthe line are maintained in the finished bag even though the actuallocation of the lower bend line may vary over a considerable extent.This method of providing rounded corners has the great advantage overthe method used-heretofore,namely, employing a shearing operation afterthe bag is formed with square corners to effect the removal of thesquare corners and the replacement thereof with rounded corners. Suchoperations on paper bags which are produced inlarge quanti tiesaddgreatly to the cost of manufacturing the bags. This additional costis entirely avoidedby the manufacture of bags in accordance with thisinvention. g

It will be appreciated by one skilled inthe art that this invention maybe incorporated in-a bag of the side fold and center seam variety, andthat various modifications may be made in the embodiment of theinvention enclosed herein such as in the formation of the curvatures ofthe side portions [6, 20, 2|, l0 and II of the bag blank withoutdeparting from the scope of the invention as set forth in the followingclaims.

Whatis claimed is:

1. The method of producing bags comprising cutting a strip of materialto form a succession of bag blanks and cutting contoured indentations inthe edges of the strip in the regions thereof in which the top andbottom corners of each bag will be formed, the indentations each beingin the form of a concave surface joining at least one convex surfaceextending inwardly of the portion of the strip which is to form thefinished edge of the bag, folding each blank with the bend linesextending transversely across the top and bottom of the bag andterminating in concave surfaces of saidindentations and displaced fromthe bases thereof, and sealing the blanks to form finished bags. I j

2. The method of producing bags comprising cutting a strip of materialto form a succession of bag blanks and cutting contoured indentations inthe edges of the strip in the regions thereof in which the top andbottom corners of each bag will be formed, the indentations each beingin the form of a concave surface joining at least one convex surfaceextending inwardly of the portion of the strip which is to form thefinished edge of the bag, folding each blank with the bend linesextending transversely across the top and bottom of the bag andterminating at or generally adjacent to points of tangency of each ofsaid concave surfaces and an adjacent convex surface, and sealing theblanks to form finished bags.

WALTER S. BLIZARD.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,884,468 Winkler Oct. 25, 1932 2,054,833 Potdevin Sept. 22,1936 2,091,796 Potdevin et a1 Aug. 31, 1937 2,115,281 Potdevin Apr. 26,1938 2,433,867 Ringler Jan. 6, 1948 2,487,643 Frischer Nov. 8, 19492,558,780 Piazze July 3, 1951

